In the production of semiconductor devices and liquid crystal displays, scaling-down technologies have rapidly been developed with the progress of a lithography method, recently. As one of resist materials satisfying the conditions of high resolution which can reproduce a pattern having a small size, a chemically amplified photoresist composition containing a base resin whose alkali solubility changes by an action of an acid, and an acid generator which generates an acid upon exposure is known. The chemically amplified photoresist composition includes a negative chemically amplified photoresist composition containing an acid generator, a crosslinking agent and an alkali soluble resin as a base resin, and a positive chemically amplified photoresist composition containing an acid generator and a resin whose alkali solubility is enhanced by an action of an acid.
Japanese Unexamined Patent Application, First Publication No. Hei 5-249676 relates to a chemically amplified negative photoresist composition and, in the example of the paragraph [0048], there is described a method for forming a resist layer by coating a resin composition containing poly(hydroxybenzylsilsesguioxane) on a layer made of a hard-baked diazoquinone novolak resin.